//
// Created by huyangbing on 2024/12/11.
//


#pragma GCC warning "Just FYI!"
#include <stdbool.h>
#define  PI 3.14
#define SQUARE(x) (x*x)
int main2(void){
#if defined PI
    //some specific calculations
  const double area=SQUARE(5)*PI;
  const bool isAreaGT100= area>100.0;
#endif
    return 0;
}